CISC & RISC

• What are the two main categories of instruction sets in computers?

  Complex Instruction Set Computer (CISC) and Reduced Instruction Set Computer (RISC)
• What is the instruction set in a computer?

  It is the set of all instructions written in machine code that can be recognized and executed by a CPU.
• What is the purpose of the execution unit in a computer?

  It carries out all calculations.
• How many registers are available in the execution unit as mentioned in the video?

  Six registers
• If the first number is stored in memory location $0000$ and the second number in $0001$, where should the product be stored?


  In memory location $0010$
• What does the CISC architecture aim to achieve in terms of assembly code?

  It aims to complete tasks in as few lines of assembly as possible.
• What is an example of a complex instruction in CISC?

  The instruction for multiplying two numbers, referred to as 'malt'.
• How does the execution time of CISC instructions compare to RISC instructions?

  CISC instructions may take more than one machine or clock cycle to execute.
• Which architecture is mainly found in desktop computers and laptops?

  CISC architecture
• What is the primary goal of RISC processors?

  To use simple instructions executed within a single machine or clock cycle.
• How many lines of assembly are needed in RISC to perform the same task that CISC does in one line?

  Four lines of assembly
• Why does RISC require more RAM compared to CISC?

  Because more lines of assembly instructions are needed to perform tasks.
• What is a benefit of RISC architecture in terms of instruction execution?

  Each instruction can be completed in a single clock cycle.
• What is pipelining in the context of RISC architecture?

  It is a method to speed up the processor by allowing multiple instructions to be processed simultaneously.
• In what types of devices has RISC architecture become popular?

  Low power and portable devices such as smartphones and tablets.
• What percentage of all processors in use today are based on RISC architecture?

  Over 90 percent
• What are the key differences between CISC and RISC architectures?

  • CISC uses complex instructions, RISC uses simple instructions.
  • CISC aims for fewer lines of assembly, RISC requires more lines.
  • CISC may take multiple clock cycles, RISC aims for single clock cycle execution.
  • CISC is more common in desktops, RISC is prevalent in portable devices.
• What is the performance equation in relation to CISC and RISC?

  CISC minimizes instructions per program while sacrificing cycles per instruction; RISC reduces cycles per instruction at the cost of more instructions.
• How does the number of instructions in CISC compare to RISC?

  CISC has a lot more instructions than RISC.
• What was a major setback for the emergence of RISC architecture?

  The dominance of Intel's CISC processors and their influence in the market.
• What is the current status of Intel's x86 processors in relation to CISC architecture?

  They are arguably the only chips that retain CISC architecture.
• How has the reduction in RAM prices affected RISC architecture?

  It has made RISC's emphasis on software over hardware ideal.
• What trend is observed in the sales of RISC-based processors compared to Intel's CISC versions?

  Sales of RISC-based processors far outstrip Intel's CISC versions.